7/02/2008

IndiaThe west coast, especially the Konkan-Mumbai-South Gujarat belt, has come in for a battering for the second time this monsoon in a pattern best attributed to a recurrent sea-based phenomenon – a positive Indian Ocean Dipole (IOD). The west coast and parts of central India are witnessing what looks like a third successive surplus monsoon phase instigated by a RARE third-in-a-row positive IOD event. India Meteorological Department has now put the IOD on the same keel as the Pacific-generated El Nino/La Nina with regard to comparable influence on the monsoon. The IOD event might just help the monsoon deliver more rain than what long-range forecasts appeared to credit it with. A positive IOD occurs when the seesawing sea surface temperatures leaves a warming anomaly in the West Indian Ocean aiding convection and precipitation. In this manner, the monsoon gets an induced southwesterly ‘push’ that is reflected in the overall output over the landmass. It is EXTREMELY UNUSUAL that a third consecutive positive IOD has evolved this year following those in 2006 and 2007. “As far as we know, THERE IS NO SUCH OCCASION IN THE PAST 100 YEARS when we had three consecutive positive IODs.”